I have a catch-all email address for my domain name email and I noted a lot of spam from LinkedIn for random usernames (like firstname.lastname@example.org - that do not even exist), and I have figured out they are leaking my email address! And my bad: I hadn't used HideMail.app or Hide My Email service from Apple for it...
As I know now, LinkedIn has the option to control who can see your email address on your profile and in this small guide I will show you how.
To open this section, on the desktop version of their site click "Me":
Click "Settings & Privacy":
And only now you can change your email visibility and hide it from robots and spammers:
Click "Only visible to me" and you are done.
There is another option, that works for any website – you can also generate an email alias with my HideMail.app or its browser extension (Chrome, Firefox). In case of email leaks leading to spam or unwanted messages, you have the option to switch to a new email alias and deactivate forwarding for the previous one.